We received a new batch of Dell desktops which included M.2 SSD drives. We included the drivers required for the WinPE, as well as added them within HII, however upon the first reboot, Windows ended up going to a boot-loop. After much research, we discovered the issue is that Windows 7 does not natively support the M.2 interface or the Skyline Chipsets.
In order to resolve this, there are two windows hotfixes that need to be installed in your golden image, right before the sys-prep phase.
More details can be found in the following article from Dell, including links to the two required hotfixes to add the support:
Hope that helps,